1. Field of the Invention
The present invention relates to a junction connector incorporated into wire harnesses used in automobiles. More particularly, the invention concerns a junction connector, in which electrical cables can be connected from different directions.
2. Description of Background Information
The wiring of harnesses in an automobile also involves the installation of electrical connector housings, such as junction boxes, comprising internal circuits. When a splicing operation cannot be carried out in the internal circuits, the junction connector is connected to electrical cables, prior to the splicing operation. In such a case, junction connectors having a structure shown in FIG. 1 are commonly used.
The above junction connector 1 includes a case 2 with a fitting recess 1a. The fitting recess contains a plurality of junction bus bars 3 provided with respective tabs 3a. Electrical cables w are branched out from a wire harness W/H. The ends of such electrical cables w are provided with terminals. These terminals are inserted into a connector 4 and locked therein. The connector 4 is then engaged with the fitting recess 1a in the junction connector 1 and locked, whereby the electrical cables w are joined. The connector 4 and the junction connector 1 are bound to the wire harness W/H by taping.
In the above junction connector 1, the tabs 3a of the junction bus bars 3 are oriented in the same direction. Moreover, the junction connector 1 has only one fitting recess 1a into which the counterpart connector 4 is fitted. Because of this single orientation of the fitting recess 1a, the junction connector 1 can receive the counterpart connector 4 only from one direction.
As shown in FIG. 2, the wire harnesses W/H, e.g. W/H-1, -2, -3 and -4 may be wired in a T or cross configuration. However, the junction connector 1 can receive only one counterpart connector 4 from one direction. Therefore, when some electrical cables of these wire harnesses W/H need to be spliced, the electrical cables to be spliced are forcibly inserted into a wire harness W/H, as shown in FIG. 1, so that the wire harnesses W/H are connected to the junction connector 1.
In the above structure, the wire harnesses W/H, and the constituent electrical cables w connecting to the junction connector 1, are not configured in the most suitable way. Furthermore, setting-up positions of the junction connector become restricted, so that the junction connector cannot always be placed appropriately in the limited space of an automobile.
In view of the above, an object of the present invention is to provide a junction connector which can be connected from a plurality of directions, enables optimum distributions of wire harnesses, and which can be arranged in an appropriate position inside the effective space of an automobile.
To this end, there is provided a junction connector including a shell which contains junction circuits and at least two connector-fitting portions oriented in different directions. The junction circuits includes at least a first bus bar layer and a second bus bar layer, which include first and second bus bars, respectively. Further, the first and second bus bars have two respective end tabs and are aligned at a given interval from each other in the same direction, respectively. The second bus bar layer is then superposed on the first bus bar layer such that the direction of the second bus bars are skewed relative to that of the first bus bars, thereby forming cross points between the first bus bars and the second bus bars. The first and second bus bars are then bonded through the cross points, thereby forming junction circuits.
In this junction connector structure, the orientation of connector-fitting portions can be very easily arranged in different directions. Accordingly, when electrical cables are splice-connected through the junction connector, there is no need to group them in one wire harness. The circuits can thus be designed as a function of the wired condition of wire harnesses and/or the set-up space for the junction connector. As a result, wire harnesses can be divided in an optimum way.
In the above junction connector, the shell defines peripheral rims. The second bus bar layer may then be superposed on the first bus bar layer such that the second bus bars are arranged perpendicular to the first bus bars. Further, the shell may include at least three connector-fitting portions which are provided on the peripheral rims and separated at an angle of 90 degrees from each other around the center axis of the shell. The connector-fitting portions may then contain the end tabs of the first and second bus bars.
As a variant, at least one of the at least first and second bus bar layers may include at least one bus bar having upwardly- and/or downwardly-bent end tabs, and the shell may include corresponding upward- and/or downward connector-fitting portions.
The connector-fitting portions may be arranged at an angle of 90 degrees from each other in the horizontal direction, measured around the center axis of the shell. Further, an upward and a downward connector-fitting portion may be added, bringing the total number of connector-fitting portions to six.
Where necessary, the number of bus bar layers may be more than two. A bus bar layer may be added in a crossed direction over the adjacent bus bar layer, but it can also be laid out at a desired skewed angle, e.g. at 45 degrees. In this manner, multi-directional connector-fitting portions may be produced.
Preferably, an insulating sheet is interposed between the at least a first bus bar layer and the second bus bar layer. The insulating sheet is provided with openings at the positions corresponding to the cross points. The first bus bars included in the first bus bar layer are then bent into the openings, so that they are brought into contact with the second bus bars included in the second bus bar layer, and joined therewith.
As a variant, the junction connector further includes a third bus bar layer with corresponding third bus bars and end tabs likewise arranged. The third bus bar layer is then superposed on the second bus bar layer such that the direction of the third bus bars is skewed relative to that of the second bus bars, thereby forming cross points between the second bus bars and the third bus bars. The second and third bus bars are then bonded through the cross points, thereby forming junction circuits.
Preferably, a second insulating sheet is interposed between the second bus bar layer and the third bus bar layer. The second insulating sheet is then provided with openings at positions corresponding to the cross points. Subsequently, the second bus bars and the third bus bars are bent into the openings, so that the second bus bars are brought into contact with the third bus bars through the openings, and bonded therewith.